JPH03107331A - Programmable power supply - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Summary] The present invention relates to a programmable power supply used when testing devices such as ICs and LSIs, and the present invention relates to a programmable power supply used when testing devices such as ICs and LSIs. In order to prevent the system from being destroyed, a main power supply circuit that can be set to a predetermined voltage value or current value, and a main power supply circuit that can be set to a predetermined voltage value or current value, is connected to each of the plurality of terminals of the device under test to set the predetermined voltage value. , or a plurality of contact portions that supply current in parallel, and a clamp circuit provided between the contact portions and the main power source corresponding to each of the contact portions.

[Industrial application field]

The present invention relates to the structure of a device power supply in a tester for IC or the like.

[Conventional technology]

I for inspecting the operation of IC devices including LSI etc.
The C tester is configured so that different voltages or currents are supplied depending on the internal circuit, capacity, etc. of the IC device under test. As shown in Figure 3, an IC tester usually includes a main power circuit 1 that generates the necessary voltage or current, and a device connected to the main power circuit and in contact with a power terminal 3 of a device 4 such as an IC. It consists of a contact part 2 consisting of a contact needle or the like that supplies a predetermined voltage or current, and -
For boat fishing, a current of several tens to hundreds of mA was required to flow, but in recent years, as the capacity of ICs has increased, the power supply current of devices has also increased, and power ICs, etc. 1
Devices that require currents as high as 0A are also emerging. For this reason, it is considered to increase the current capacity by providing multiple power terminals instead of just one. In this case, it is necessary to apply current to each power supply terminal of the IC device from the main power supply of the IC tester evenly and so as not to exceed the current capacity.

In other words, when it is necessary to flow a current of 5A to one IC device, suppose that 10 power supply terminals are provided and each terminal has a current of 0.5A.
There is no problem if you let A flow through, but if the contact between power supply terminal 3 and contact 2 in one part of the IC device becomes poor, the other power supply terminals will be exposed to a voltage that exceeds the allowable amount. The disadvantage is that current flows and the device or measurement system is destroyed. The conventional programmable power supply circuit described above has a configuration that can be adjusted by appropriate means so that the optimum current value or voltage value is supplied to the IC device under test in the main power supply circuit. The plurality of contacts 2 that come into contact with the plurality of power supply terminals of the device under test are simply connected in parallel with one main power supply 1, and do not control any changes in the current of each power supply terminal of the device under test. do not have.

[Problem to be solved by the invention]

The present invention improves the drawbacks of the prior art described above, and even if a contact failure occurs between some of the contact parts of the IC tester and the power supply terminal of the IC device under test, the current exceeds the allowable amount of the power supply terminal. The object of the present invention is to provide a programmable power supply circuit that can prevent the inflow and damage to device circuits and measurement systems.

[Means to solve the problem]

The present invention employs the following technical configuration to achieve the above object. That is, a main power supply circuit that can be set to a predetermined voltage or current value, and a plurality of contacts that are connected to each of the plurality of terminals of the device under test and supply the predetermined voltage or current in parallel. The programmable power supply includes a clamp circuit provided between the contact part and the main power supply opening corresponding to each of the contact parts.

In other words, in the present invention, a clamp circuit is provided between one main power supply and a contact portion that contacts the power supply terminals of a plurality of devices under test connected in parallel to the main power supply. By adjusting the clamp circuit section, it is possible to set an appropriate lamp current by dividing the current into the contact sections according to the number of power supply terminals and by adjusting the clamp circuit section.

[For production]

Since the present invention has the above-mentioned configuration, even if a contact failure occurs in one part, a current exceeding the allowable current will not flow to other power supply terminals. There is no risk of circuit damage or measurement system destruction.

〔Example〕

A specific example of the programmable power supply according to the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram explaining the principle of the present invention.

One main power supply circuit 1 (PPS: Progra
A plurality of clamp circuits 5 (re-lamp 5-1, clamp 5-2, . . . , clamp 5-n) are provided in parallel with each other in parallel to the number of power supply terminals of the device under test. Clamp circuit 5
A needle-shaped contact portion 2 that comes into contact with the power supply terminal 3 of the device 4 is provided at each tip.

The main power supply 1 is called PPS and is used to set the power supply voltage and clamp current required for the measurement system and the device under test 4 as a whole. It has a structure in which desired current and voltage values can be arbitrarily set through arithmetic processing. In the present invention, the main power supply 1 also has the function of determining the maximum value of the entire clamp current. Furthermore, the set value of the main power supply l can be set to a different value if the device under test is changed.

Also, clamp circuit 5 (5-1, 5-2,...5-n)
As mentioned above, the limit value is set so as not to exceed the allowable current amount of each power supply terminal of the IC device, and this is also preferably set or changed by program processing, so it is preferable.

The current values set in each of the clamp circuits may be the same, but may be set to different values as appropriate depending on the power supply terminal of the device under test.

Further, the clamp current value 2 may be changed every time the device is changed. In other words, in the present invention, the clamp current flowing through each clamp circuit 5 is set to ll+1!・・・
・1. When, the current ■ is the current iI ten lightning current 2 . . . current 17. Note that the structure of the clamp circuit is not particularly limited, and a clamp circuit used for boat fishing may be used. However, as mentioned above, it is preferable that the clamp value be varied by a program.A specific example of the present invention will be explained with reference to FIG.

In FIG. 2, a plurality of parallel lines in which clamp circuits 5 and contacts 2 are connected in series are selected by appropriate selection means 6.
The desired clamp circuit 5 and contact 2 are selectively connected to the setting power supply circuit 1 during measurement work. The selection means 6 includes a plurality of switches S corresponding to each line.
, ~Sn, and each switch 31 to S7 may be constituted by a well-known switch means such as a relay or an electronic switch. By selectively operating one of S and S7, the main power source and the contact portion 2 of the clamp circuit 5 are connected to perform measurement.

Furthermore, in the present invention, even if excessive power tries to flow through other lines due to poor contact between the contact portion 2 and the power supply terminal 3 of the device during device measurement as described above, the clamp circuit provided on each line Control is performed so that only the maximum allowable amount of current set by the clamp circuit flows through the device.

Therefore, there is no risk that the device under test will be destroyed.

However, in the present invention as well, if a contact failure occurs between one contact portion and the power supply terminal of the device as described above, and the current in that line does not flow, at the same time, other contacts connected to the main power circuit The current that should have flowed through the line begins to flow through the line.

At that time, there is no problem if there is room for extra current to flow through the other lines mentioned above, but if there is no room at all in that line, the current flowing through the main power supply will decrease, and the overall voltage of the main power supply will decrease. There was a risk that the device would be dropped and the device test would not be performed using the preset normal values. Therefore, in Fig. 2, the clamp circuit 5
A clamp detection circuit 8 is installed in the clamp circuit 5, and when a current exceeding the clamp current value flows into the clamp circuit 5, the clamp detection circuit is activated and an alarm 9 is activated, which alerts the operator to an abnormality. to inform about something.

As a result, the operator immediately stops measuring the device under test, checks the cause of the contact failure, cleans the contact portion, etc., and then restarts the measurement.

〔effect〕

As described above, according to the present invention, by limiting the current of each power supply terminal even for an IC device that has a large number of power supply currents, it is possible to prevent destruction of the device and measurement system due to overcurrent.

Furthermore, since at least the clamp circuit is provided with a clamp detection circuit that detects that the clamp has operated, measurement abnormalities can be determined at an early stage, contributing to improvement in measurement efficiency and measurement accuracy.

[Brief explanation of drawings]

FIG. 1 is a diagram explaining the principle of the present invention. FIG. 2 is a diagram showing one specific example of the programmable power supply according to the present invention. FIG. 3 is a diagram showing a conventional programmable power supply. l...Main power circuit, 2...Contact part,
3... Power supply terminal, 4... Device (IC etc.), 5... Clamp circuit, 6... Switch means, 7... Control circuit, 8... Clamp detection circuit, 9... alarm. Diagram for explaining the principle of the present invention

Claims (1)

[Claims] 1. A main power supply circuit that can be set to a predetermined voltage value or current value, and connected to each of a plurality of terminals of the device under test to supply the predetermined voltage or current in parallel. A programmable power supply comprising: a plurality of contact portions for supplying power; and a clamp circuit provided between the contact portions and the main power supply portion, corresponding to each of the contact portions. 2. The programmable power supply according to claim 1, further comprising a clamp detection alarm circuit that detects and notifies the operation of the clamp circuit. 3. Between the main power circuit and the plurality of contacts,
2. The programmable power supply according to claim 1, further comprising selection means for selecting a predetermined contact portion and connecting it to the main power supply.